Co:Z SFTP with Dataset Support - User's Guide

1. Introduction

The "IBM Ported Tools for z/OS" product includes a port of the popular OpenSSH tools. These tools provide for secure remote login and program execution (ssh) and file transfer (sftp and scp). The sftp and sftp-server commands implement a file transfer program that is similar to ftp, but use ssh for their underlying secure transport. The sftp specification [1] accounts only for binary transfers. The IBM z/OS sftp client has been enhanced to support ASCII-EBCDIC conversion. Dataset support is not provided.

The Co:Z Co-Processing Toolkit for z/OS includes a new port of the OpenSSH sftp-server subsystem (v5.0p1) which adds support for MVS datasets, text mode transfers and SMF 119 accounting. This subsystem must be installed with an existing OpenSSH implementation on z/OS, such as IBM Ported Tools for z/OS (SSH). Also included is an enhanced sftp client for z/OS which allows for z/OS client initiated transfers to remote systems.

This document describes how to configure OpenSSH on z/OS so that either the original (IBM) sftp-server or the Co:Z sftp-server can be used in the same instance of sshd, selectable on a per user basis.

NOTE: Co:Z SFTP is NOT supported by IBM.

1.1 Features

  • Works with most existing sftp clients (see the section called “Client Requirements”).

  • Transfer datasets via the get and put commands

  • Navigate z/OS catalogs via the cd command.

  • List dataset information and PDS directories via the ls command.

  • Records SMF 119 records if user has BPX.SMF SAF authorization.

  • Supports direct access to datasets which can be opened in sequential, record mode by the fopen() C-library routine. This includes:

    • MVS sequential datasets (QSAM, BSAM, VSAM)

    • PDS and PDSE members

    • SYSOUT datasets, including the MVS internal reader

  • Supports text or binary conversion via flexible line-termination rules:

    • Cr, Lf/Newline, CrLf, Cr and/or Lf, RDW, none

  • Supports flexible record padding / overflow rules

  • Can specify dataset dynamic allocation (BPXWDYN) keywords

1.2 Supported Environments

z/OS Host Requirements

Client Requirements

  • Wide variety of operating systems, including Windows, *IX variants, z/OS...

  • sftp clients supporting SSH File Transfer Protocol, such as:

    • Co:Z sftp client for z/OS

    • OpenSSH

    • puTTy psftp

    • winSCP

    • gFTP